Search PubMed⌕ Search

Biomedical subjects

Y Ueda

Publications and source records attributed to Y Ueda.

At least 1,009 records · Page 56Linked to original sources
PubMed1985

[Mitral valve replacement with preservation of whole papillary muscles and chordae tendineae].

A total of 20 patients underwent mitral valve replacement (MVR) with preservation of the papillary muscles (PM) and chordae tendineae (CT) with the object of maintaining left ventricular contractility and decreasing the risk of left ventricular rupture after surgery. The patients comprised of 8 males and 12 females whose ages ranged from 33 to 67 years. In 8 patients, the posterior leaflet was left in place and in 12, the CT to the anterior leaflet were also preserved by excision of the central portion and reattachment of the rest of the leaflet to the appropriate commissural regions. St. Jude Medical valves were exclusively employed as a substitute. Reasons for MVR were isolated MR in 12 cases, MRs in 5 and MSr in 3. There were one operative, one hospital and one late death respectively. Postoperative C.I. increased from 2.65 +/- 0.48 to 3.8 +/- 0.75 ml/min./M2 and LVEF increased from 55.1 +/- 11.4 to 63.4 +/- 13.4%. The area method showed marked improvement of segmental wall motion in anterolateral regions. Chordal shortening also disclosed improvement in long axis. Preservation of papillary muscles and chordae tendineae during MVR has been found to have a beneficial effect on postoperative left ventricular contractility.

Adult↗
PubMed1984

Device for determining location of an endotracheal catheter tip.

The location of a catheter's tip in the bronchi may be determined using a stethoscope and an audible sound that has a frequency of 558 Hz and a sound pressure of 136 dB for the adult. The device is easy and safe to use, and has been used in a broad range of patients for over 4 yr without sequelae.

Auscultation↗
PubMed1984

Hemangioblastoma presenting with intraparenchymatous hemorrhage.

The authors report six cases of hemangioblastoma presenting with apoplectic symptoms but with no history related to the tumor. In each case, computerized tomography disclosed an intraparenchymatous hemorrhage, which was located supratentorially in four and in the cerebellum in the remaining two. Angiography revealed an abnormal vascular blush in two cases, but no abnormal vessels or tumor blush in the other four. In all cases, a solid tumor with abnormal vessels, such as red veins and feeding arteries, was found within or adjacent to the hemorrhage at surgery. The possibility of hemangioblastoma should be kept in mind as a cause of intraparenchymatous hemorrhage, particularly subcortical. Evacuation of the hematoma should be carefully carried out, and the whole hematoma wall should be thoroughly investigated for abnormal vessels or a solid mass.

Adult↗
PubMed1984

Synergistic activity of astromicin and beta-lactam antibiotics against Pseudomonas aeruginosa in vitro and in vivo.

Synergistic activity of astromicin and an antipseudomonal beta-lactam antibiotic such as piperacillin, cefsulodin or carbenicillin against Pseudomonas aeruginosa was demonstrated in vitro and in vivo. Synergy in vitro was observed more often when astromicin was combined with piperacillin or cefsulodin than when it was combined with carbenicillin. The combination of astromicin with piperacillin showed a bactericidal activity against Pseudomonas aeruginosa at a bacteriostatic concentration of each antibiotic alone. The synergy observed in vitro was reproduced against experimental mouse infections, and the astromicin-piperacillin or cefsulodin combination produced significantly greater protective effects than the single use of individual antibiotics.

Aminoglycosides↗
PubMed1984

Dehydration and delayed proton equilibria of red blood cells suspended in isosmotic phosphate buffers. Implications for studies of sickled cells.

PO4 buffers isosmotic with plasma or phosphate-buffered saline solution with a substantial proportion of PO4 are often used to wash and suspend red blood cells in studies of respiratory or sickling behavior. Measurements of sequential changes in mean cell hemoglobin concentration, pH, and ion content of red blood cells suspended in 295 mOsm Na-phosphate, pH 7.4, at 23 degrees or 37 degrees C, showed (1) rapid, persistent cell dehydration (mean cell hemoglobin concentration greater than 40 gm/dl) caused initially by Cl- efflux and later by replacement of monovalent Cl- by divalent HPO=4; and (2) temporary reversal of membrane pH gradients with normalization time (30 to 120 minutes) dependent on factors controlling the rate of phosphate-chloride exchange. Sequential equilibration of red blood cells in isosmotic citrate (impermeable) followed by PO4 demonstrated the two stages of the observed shifts in PO4 alone, and red blood cells suspended in 0.15 mol/L 32PO4 at 37 degrees C showed PO4 influx consistent with pH equilibrium kinetics. Sickle trait red blood cells deoxygenated at 37 degrees C, pH 7.4, in plasma or 10 mmol/L HEPES-buffered saline solution showed only 6% to 20% sickling. In isosmotic PO4, mean cell hemoglobin concentration was 40 to 41 gm/dl with approximately 80% sickling. In phosphate-buffered saline solution containing 70 mmol/L PO4, red blood cells showed smaller, similar changes (mean cell hemoglobin concentration approximately 38 gm/dl) with a longer equilibration period and deoxygenated sickle trait cells showed 40% sickling. The altered properties of red blood cells suspended in PO4 or phosphate-buffered saline solution were neither intended nor appropriate for many studies using these media, particularly with hemoglobin S-containing red blood cells, and interpretations of reported results must be reassessed in light of these findings.

Anemia, Sickle Cell↗
PubMed1984

Activation of immune regulatory circuits among OKT4+ cells by autologous mixed lymphocyte reactions.

We examined the nature of an autologous mixed lymphocyte reaction (AMLR) using T cell subsets defined by monoclonal antibodies. Cells capable of proliferating in the AMLR were demonstrated to reside in an OKT4+, but not an OKT8+, cell subset. With regard to the role of the T cell subsets recoverable from AMLR in the immune regulation, OKT4+ cells isolated from cells that had been activated for 3 days in AMLR did help pokeweed mitogen (PWM) stimulated immunoglobulin synthesis by autologous B cells. However, the OKT4+ cells activated for 6 days in AMLR exerted strong suppressor activity for PWM-induced immunoglobulin synthesis. Irradiation with 1,500 rad on activated OKT4+ cells in AMLR for 6 days not only eliminated the suppressor function but allowed for re-emergence of helper function. Cells exerting suppressor activity alone were recovered from OKT8+ cells stimulated with or without autologous non-T cells. These data suggest that OKT4+ cells activated in AMLR contain two functionally different subsets; one as helper cells and the other as suppressor cells. In addition, the emergence of OKT4+ suppressor function follows activation of the OKT4+ helper population, suggesting that a part of AMLR reflects a mechanism of 'feedback suppression' among OKT4+ cells.

Antibodies, Monoclonal↗
PubMed1984

Multicenter clinical trials of cefoperazone in Japan.

The safety and clinical efficacy of cefoperazone were evaluated at 149 institutions in Japan. A total of 979 hospitalized patients were treated with cefoperazone alone for 1,059 infections. In the 984 infections evaluated, there was an overall satisfactory clinical response in 824 (83.7%). Cefoperazone was effective in 83.0% of the respiratory tract infections, 84.9% of urinary tract infections, and 89.6% of hepatobiliary tract infections. Clinical response was satisfactory in 90% or more of the cases in which Escherichia coli, Serratia sp, Haemophilus influenzae or Staphylococcus sp were isolated. Sixty percent to 90% of the infections with Klebsiella sp, Enterobacter sp, Proteus sp, and Pseudomonas aeruginosa responded satisfactorily to cefoperazone. Cefoperazone was effective in 76.2% of 260 evaluated cases that had failed to respond to prior treatment with other cephalosporins. The adverse reactions that occurred in 19 (1.9%) of the 979 patients included rash (1%), diarrhea (0.6%), and fever (0.4%). Cefoperazone appears to be extremely useful in the treatment of various infections in hospitalized patients.

Adult↗
PubMed1984

Effects of carbon dioxide and pH variations in vitro on blood respiratory functions, red blood cell volume, transmembrane pH gradients, and sickling in sickle cell anemia.

Findings that polymerization of hemoglobin S is an oxygen-linked function, and that CO2 has an O2 affinity-independent effect on deoxyhemoglobin S polymerization suggests that varying PCO2 might have different effects on respiratory functions and other red blood cell properties of blood in sickle cell anemia (SS) compared with normal blood (AA). We examined the O2 affinity, Bohr effect, transmembrane pH gradient, mean cell hemoglobin concentration, and red blood cell sickling at half O2 saturation in whole SS and AA blood during CO2 titration and acid-base titration at three PCO2 levels, 10, 40, and 80 mm Hg. The CO2-induced Bohr effect of SS blood was considerably larger than normal (maximum, 0.91, referred to cell pH) and similar to that found with acid-base titration at PCO2 of 40. In contrast to AA blood, SS blood showed an increased O2 affinity when PCO2 was raised from 40 to 80, and at half O2 saturation showed biphasic or sigmoid Bohr curves, a fall in transmembrane pH gradient with rising PCO2, and an absence of the normal cell volume increase at low pH and PCO2. Sickling of SS cells at half O2 saturation was partly inhibited by increasing PCO2, particularly in the higher pH ranges. These complex differences in the behavior of SS blood are interpreted in terms of the balancing of several effects: the lowering of hemoglobin O2-affinity by polymerization, low pH and increased CO2 binding, inhibition of hemoglobin S polymerization by CO2 binding to beta s-chain amino termini, differences between hemoglobin S and A in competitive binding of CO2 and 2,3-diphosphoglycerate at different pH levels, and an increased net negative charge exhibited by intracellular deoxyhemoglobin S polymers. From a clinical standpoint, in the absence of hypoxia or acidosis, an increased blood PCO2 might have a beneficial effect by inhibiting red blood cell sickling, whereas a metabolic acidosis, with low blood pH and PCO2, would be very hazardous.

2,3-Diphosphoglycerate↗